Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
SiCArthur Thomas , Gemstones (2009)
ZrO 2Arthur Thomas , Gemstones (2009)